Split brain

Question 1

Which part of the brain is cut in split brain?

Answer 1

Corpus callosum

Question 2

Who devised the procedure to show how 2 seperated hemispheres deal with speech and vision?

Answer 2

Sperry (1968)

Question 3

Why was the split brain surgery conducted?

Answer 3

To reduce epileptic fits. These fits connections are cut splitting the brain in 2 halves.

Question 4

Procedure of Sperry’s research

Answer 4

• 11 people with split brain
• Image projected onto RVF and the same/different image also shown to LVF
• Normal brain would share info across hemispheres
• Split brain can’t communicate the picture between the 2 hemispheres

Question 5

Results of Sperry’s research

Answer 5

• When shown image to RVF, they could describe what they had seen
• Could not describe if it was shown to LVF, they would say nothing was there
• This is because the LH is responsible for language, they lacked words to explain what they had seen

Question 6

Strength - further support for split brain findings

Answer 6

• Gazzaniga showed split brains performed better than connected on some tasks
• Faster at identifying the odd one out
• Kingston et al (1995): in normal brain, the LH’s better cognitive strategies are ‘watered down’ by inferior RH
• Supports Sperry’s early findings that the left and right brain are distinct

Question 7

Limitation - Casual relationships are hard to establish, there are generalisation issues

Answer 7

• Sperry’s patients were compared to a ‘neurotypical control group’, none had epilepsy (a confounding variable)
• Any differences between the groups may have been the results of epilepsy and no split brain